include/linux/kernel.h

   1 #ifndef _LINUX_KERNEL_H
   2 #define _LINUX_KERNEL_H
   3
   4 /*
   5  * 'kernel.h' contains some often-used function prototypes etc
   6  */
   7
   8 #ifdef __KERNEL__
   9
  10 #include <stdarg.h>
  11 #include <linux/linkage.h>
  12 #include <linux/stddef.h>
  13 #include <linux/types.h>
  14 #include <linux/compiler.h>
  15 #include <linux/bitops.h>
  16 #include <linux/log2.h>
  17 #include <asm/byteorder.h>
  18 #include <asm/bug.h>
  19
  20 extern const char linux_banner[];
  21
  22 #define INT_MAX         ((int)(~0U>>1))
  23 #define INT_MIN         (-INT_MAX - 1)
  24 #define UINT_MAX        (~0U)
  25 #define LONG_MAX        ((long)(~0UL>>1))
  26 #define LONG_MIN        (-LONG_MAX - 1)
  27 #define ULONG_MAX       (~0UL)
  28 #define LLONG_MAX       ((long long)(~0ULL>>1))
  29 #define LLONG_MIN       (-LLONG_MAX - 1)
  30 #define ULLONG_MAX      (~0ULL)
  31
  32 #define STACK_MAGIC     0xdeadbeef
  33
  34 #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
  35 #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
  36
  37 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  38 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  39 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  40 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
  41
  42 #define KERN_EMERG      "<0>"   /* system is unusable                   */
  43 #define KERN_ALERT      "<1>"   /* action must be taken immediately     */
  44 #define KERN_CRIT       "<2>"   /* critical conditions                  */
  45 #define KERN_ERR        "<3>"   /* error conditions                     */
  46 #define KERN_WARNING    "<4>"   /* warning conditions                   */
  47 #define KERN_NOTICE     "<5>"   /* normal but significant condition     */
  48 #define KERN_INFO       "<6>"   /* informational                        */
  49 #define KERN_DEBUG      "<7>"   /* debug-level messages                 */
  50
  51 extern int console_printk[];
  52
  53 #define console_loglevel (console_printk[0])
  54 #define default_message_loglevel (console_printk[1])
  55 #define minimum_console_loglevel (console_printk[2])
  56 #define default_console_loglevel (console_printk[3])
  57
  58 struct completion;
  59 struct pt_regs;
  60 struct user;
  61
  62 /**
  63  * might_sleep - annotation for functions that can sleep
  64  *
  65  * this macro will print a stack trace if it is executed in an atomic
  66  * context (spinlock, irq-handler, ...).
  67  *
  68  * This is a useful debugging help to be able to catch problems early and not
  69  * be bitten later when the calling function happens to sleep when it is not
  70  * supposed to.
  71  */
  72 #ifdef CONFIG_PREEMPT_VOLUNTARY
  73 extern int cond_resched(void);
  74 # define might_resched() cond_resched()
  75 #else
  76 # define might_resched() do { } while (0)
  77 #endif
  78
  79 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
  80   void __might_sleep(char *file, int line);
  81 # define might_sleep() \
  82         do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
  83 #else
  84 # define might_sleep() do { might_resched(); } while (0)
  85 #endif
  86
  87 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  88
  89 #define abs(x) ({                               \
  90                 int __x = (x);                  \
  91                 (__x < 0) ? -__x : __x;         \
  92         })
  93
  94 #define labs(x) ({                              \
  95                 long __x = (x);                 \
  96                 (__x < 0) ? -__x : __x;         \
  97         })
  98
  99 extern struct atomic_notifier_head panic_notifier_list;
 100 extern long (*panic_blink)(long time);
 101 NORET_TYPE void panic(const char * fmt, ...)
 102         __attribute__ ((NORET_AND format (printf, 1, 2)));
 103 extern void oops_enter(void);
 104 extern void oops_exit(void);
 105 extern int oops_may_print(void);
 106 fastcall NORET_TYPE void do_exit(long error_code)
 107         ATTRIB_NORET;
 108 NORET_TYPE void complete_and_exit(struct completion *, long)
 109         ATTRIB_NORET;
 110 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 111 extern long simple_strtol(const char *,char **,unsigned int);
 112 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 113 extern long long simple_strtoll(const char *,char **,unsigned int);
 114 extern int sprintf(char * buf, const char * fmt, ...)
 115         __attribute__ ((format (printf, 2, 3)));
 116 extern int vsprintf(char *buf, const char *, va_list)
 117         __attribute__ ((format (printf, 2, 0)));
 118 extern int snprintf(char * buf, size_t size, const char * fmt, ...)
 119         __attribute__ ((format (printf, 3, 4)));
 120 extern int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 121         __attribute__ ((format (printf, 3, 0)));
 122 extern int scnprintf(char * buf, size_t size, const char * fmt, ...)
 123         __attribute__ ((format (printf, 3, 4)));
 124 extern int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
 125         __attribute__ ((format (printf, 3, 0)));
 126 extern char *kasprintf(gfp_t gfp, const char *fmt, ...)
 127         __attribute__ ((format (printf, 2, 3)));
 128
 129 extern int sscanf(const char *, const char *, ...)
 130         __attribute__ ((format (scanf, 2, 3)));
 131 extern int vsscanf(const char *, const char *, va_list)
 132         __attribute__ ((format (scanf, 2, 0)));
 133
 134 extern int get_option(char **str, int *pint);
 135 extern char *get_options(const char *str, int nints, int *ints);
 136 extern unsigned long long memparse(char *ptr, char **retptr);
 137
 138 extern int core_kernel_text(unsigned long addr);
 139 extern int __kernel_text_address(unsigned long addr);
 140 extern int kernel_text_address(unsigned long addr);
 141 extern int session_of_pgrp(int pgrp);
 142
 143 extern void dump_thread(struct pt_regs *regs, struct user *dump);
 144
 145 #ifdef CONFIG_PRINTK
 146 asmlinkage int vprintk(const char *fmt, va_list args)
 147         __attribute__ ((format (printf, 1, 0)));
 148 asmlinkage int printk(const char * fmt, ...)
 149         __attribute__ ((format (printf, 1, 2)));
 150 #else
 151 static inline int vprintk(const char *s, va_list args)
 152         __attribute__ ((format (printf, 1, 0)));
 153 static inline int vprintk(const char *s, va_list args) { return 0; }
 154 static inline int printk(const char *s, ...)
 155         __attribute__ ((format (printf, 1, 2)));
 156 static inline int printk(const char *s, ...) { return 0; }
 157 #endif
 158
 159 unsigned long int_sqrt(unsigned long);
 160
 161 static inline unsigned long
 162 __attribute_const__ roundup_pow_of_two(unsigned long x)
 163 {
 164         return 1UL << fls_long(x - 1);
 165 }
 166
 167 extern int printk_ratelimit(void);
 168 extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
 169 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 170                                 unsigned int interval_msec);
 171
 172 static inline void console_silent(void)
 173 {
 174         console_loglevel = 0;
 175 }
 176
 177 static inline void console_verbose(void)
 178 {
 179         if (console_loglevel)
 180                 console_loglevel = 15;
 181 }
 182
 183 extern void bust_spinlocks(int yes);
 184 extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 185 extern int panic_timeout;
 186 extern int panic_on_oops;
 187 extern int panic_on_unrecovered_nmi;
 188 extern int tainted;
 189 extern const char *print_tainted(void);
 190 extern void add_taint(unsigned);
 191
 192 /* Values used for system_state */
 193 extern enum system_states {
 194         SYSTEM_BOOTING,
 195         SYSTEM_RUNNING,
 196         SYSTEM_HALT,
 197         SYSTEM_POWER_OFF,
 198         SYSTEM_RESTART,
 199         SYSTEM_SUSPEND_DISK,
 200 } system_state;
 201
 202 #define TAINT_PROPRIETARY_MODULE        (1<<0)
 203 #define TAINT_FORCED_MODULE             (1<<1)
 204 #define TAINT_UNSAFE_SMP                (1<<2)
 205 #define TAINT_FORCED_RMMOD              (1<<3)
 206 #define TAINT_MACHINE_CHECK             (1<<4)
 207 #define TAINT_BAD_PAGE                  (1<<5)
 208
 209 extern void dump_stack(void);
 210
 211 #ifdef DEBUG
 212 /* If you are writing a driver, please use dev_dbg instead */
 213 #define pr_debug(fmt,arg...) \
 214         printk(KERN_DEBUG fmt,##arg)
 215 #else
 216 static inline int __attribute__ ((format (printf, 1, 2))) pr_debug(const char * fmt, ...)
 217 {
 218         return 0;
 219 }
 220 #endif
 221
 222 #define pr_info(fmt,arg...) \
 223         printk(KERN_INFO fmt,##arg)
 224
 225 /*
 226  *      Display an IP address in readable format.
 227  */
 228
 229 #define NIPQUAD(addr) \
 230         ((unsigned char *)&addr)[0], \
 231         ((unsigned char *)&addr)[1], \
 232         ((unsigned char *)&addr)[2], \
 233         ((unsigned char *)&addr)[3]
 234 #define NIPQUAD_FMT "%u.%u.%u.%u"
 235
 236 #define NIP6(addr) \
 237         ntohs((addr).s6_addr16[0]), \
 238         ntohs((addr).s6_addr16[1]), \
 239         ntohs((addr).s6_addr16[2]), \
 240         ntohs((addr).s6_addr16[3]), \
 241         ntohs((addr).s6_addr16[4]), \
 242         ntohs((addr).s6_addr16[5]), \
 243         ntohs((addr).s6_addr16[6]), \
 244         ntohs((addr).s6_addr16[7])
 245 #define NIP6_FMT "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x"
 246 #define NIP6_SEQFMT "%04x%04x%04x%04x%04x%04x%04x%04x"
 247
 248 #if defined(__LITTLE_ENDIAN)
 249 #define HIPQUAD(addr) \
 250         ((unsigned char *)&addr)[3], \
 251         ((unsigned char *)&addr)[2], \
 252         ((unsigned char *)&addr)[1], \
 253         ((unsigned char *)&addr)[0]
 254 #elif defined(__BIG_ENDIAN)
 255 #define HIPQUAD NIPQUAD
 256 #else
 257 #error "Please fix asm/byteorder.h"
 258 #endif /* __LITTLE_ENDIAN */
 259
 260 /*
 261  * min()/max() macros that also do
 262  * strict type-checking.. See the
 263  * "unnecessary" pointer comparison.
 264  */
 265 #define min(x,y) ({ \
 266         typeof(x) _x = (x);     \
 267         typeof(y) _y = (y);     \
 268         (void) (&_x == &_y);            \
 269         _x < _y ? _x : _y; })
 270
 271 #define max(x,y) ({ \
 272         typeof(x) _x = (x);     \
 273         typeof(y) _y = (y);     \
 274         (void) (&_x == &_y);            \
 275         _x > _y ? _x : _y; })
 276
 277 /*
 278  * ..and if you can't take the strict
 279  * types, you can specify one yourself.
 280  *
 281  * Or not use min/max at all, of course.
 282  */
 283 #define min_t(type,x,y) \
 284         ({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 285 #define max_t(type,x,y) \
 286         ({ type __x = (x); type __y = (y); __x > __y ? __x: __y; })
 287
 288
 289 /**
 290  * container_of - cast a member of a structure out to the containing structure
 291  * @ptr:        the pointer to the member.
 292  * @type:       the type of the container struct this is embedded in.
 293  * @member:     the name of the member within the struct.
 294  *
 295  */
 296 #define container_of(ptr, type, member) ({                      \
 297         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
 298         (type *)( (char *)__mptr - offsetof(type,member) );})
 299
 300 /*
 301  * Check at compile time that something is of a particular type.
 302  * Always evaluates to 1 so you may use it easily in comparisons.
 303  */
 304 #define typecheck(type,x) \
 305 ({      type __dummy; \
 306         typeof(x) __dummy2; \
 307         (void)(&__dummy == &__dummy2); \
 308         1; \
 309 })
 310
 311 /*
 312  * Check at compile time that 'function' is a certain type, or is a pointer
 313  * to that type (needs to use typedef for the function type.)
 314  */
 315 #define typecheck_fn(type,function) \
 316 ({      typeof(type) __tmp = function; \
 317         (void)__tmp; \
 318 })
 319
 320 #endif /* __KERNEL__ */
 321
 322 #define SI_LOAD_SHIFT   16
 323 struct sysinfo {
 324         long uptime;                    /* Seconds since boot */
 325         unsigned long loads[3];         /* 1, 5, and 15 minute load averages */
 326         unsigned long totalram;         /* Total usable main memory size */
 327         unsigned long freeram;          /* Available memory size */
 328         unsigned long sharedram;        /* Amount of shared memory */
 329         unsigned long bufferram;        /* Memory used by buffers */
 330         unsigned long totalswap;        /* Total swap space size */
 331         unsigned long freeswap;         /* swap space still available */
 332         unsigned short procs;           /* Number of current processes */
 333         unsigned short pad;             /* explicit padding for m68k */
 334         unsigned long totalhigh;        /* Total high memory size */
 335         unsigned long freehigh;         /* Available high memory size */
 336         unsigned int mem_unit;          /* Memory unit size in bytes */
 337         char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
 338 };
 339
 340 /* Force a compilation error if condition is true */
 341 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 342
 343 /* Force a compilation error if condition is true, but also produce a
 344    result (of value 0 and type size_t), so the expression can be used
 345    e.g. in a structure initializer (or where-ever else comma expressions
 346    aren't permitted). */
 347 #define BUILD_BUG_ON_ZERO(e) (sizeof(char[1 - 2 * !!(e)]) - 1)
 348
 349 /* Trap pasters of __FUNCTION__ at compile-time */
 350 #define __FUNCTION__ (__func__)
 351
 352 /* This helps us to avoid #ifdef CONFIG_NUMA */
 353 #ifdef CONFIG_NUMA
 354 #define NUMA_BUILD 1
 355 #else
 356 #define NUMA_BUILD 0
 357 #endif
 358
 359 #endif